<template>
  <div>
      <span >全选:</span>
    <input type="checkbox" v-model="all"/>
    <button @click="fn">反选</button>
    <ul>
      <li v-for='item in arr' :key='item.name'>
        <input type="checkbox" v-model="item.c"/>
        <span>{{item.name}}</span>
      </li>
    </ul>
   </div>
</template>
 
<script>
export default {
  data() {
    return {
        arr: [
        {
          name: "猪八戒",
          c: false,
        },
        {
          name: "孙悟空",
          c: false,
        },
        {
          name: "唐僧",
          c: false,
        },
        {
          name: "白龙马",
          c: false,
        },
      ],
    };
  },
  computed:{
    all:{
      get(){
        return this.arr.every(item=>item.c)
      },
      set(value){
        // console.log(value);
        this.arr.forEach(item=>item.c=value)
      }
    }
  },
  methods:{
    fn(){
      this.arr.forEach(item=>item.c=!item.c)
    }
  }
};
</script>

<style scoped>
     
</style>